Search results

The purpose of this paper is to present a manufacturing process for wheat straw/polystyrene (PS) composite that can be expected to be a significant contribution to making effective use of agricultural residues, protecting the environment and water resources, resolving conflicts among the needs of humans, the resource base, and the environment, and establishing a society based on sustainable development.

Wheat straw and recycled PS were mixed at an ambient temperature and then hot‐pressed to prepare wheat straw/recycled PS composite, and the optimal processing factors for preparing the composite were investigated.

It was found that adding PS can reduce the quantity of diphenyl methane diisocyanate (MDI) needed and the manufacturing cost of the wheat straw/PS composite. The optimal process parameters are as follows: hot‐pressing cycle time – 7 min; temperature – 190°C, PS percentage – 35 per cent; coupling‐agent content – 3.5 per cent; and density – 0.60 or 0.65 g/cm³.

PS is a nonpolar material and wheat straw is a polar material, which makes them difficult to bond together. MDI had been found to be an effective coupling agent to improve bond strength, but was expensive.

The wheat straw/PS composite can be used for interior decoration and furniture manufacture. In the future, it could also be used in construction if its performance is improved.

Wheat straw particleboard can be made with wheat straw and recycled PS, and the mechanical properties of the board meet the Chinese National Standard.

The purpose of this paper is to assess the effects of cement‐ and earth‐plastered straw bale walls against the appropriate vertical loads.

The effects of contact between two common types of plasters and the stacked straw bale by the optimal design analysis have been assessed in this work with the use of finite element method.

Cement‐ and earth‐plastered straw bale walls have shown adequate resistance against the appropriate vertical loads and showed that the earth‐plaster can bear higher stress than the cement plastered straw bale. There is the implication that the collapse or response of the earth‐straw bale wall will be significantly higher compared to that of cement‐straw bale wall.

The stress stability obtained of the analytical walls is adequate after using the best fit variables for the wall height and thickness.

The paper shows that the allowable stresses of 70.14 kN/m² for cement plastered straw bale wall and 73.14 kN/m² for earth‐plastered straw bale wall are higher than the calculated stress values using SAP2000 of 18.836 and 64.2 kN/m² for cement plastered straw bale wall, respectively.

Discusses the thatching industry, looking at the main thatch materials together with their characteristics, to provide a brief analysis of how thatch works, in particular its water resistance. Outlines the basic items to look for when compiling an up‐to‐date report on any particular thatch. Provides a glossary of thatching terms. Suggests that each thatched roof should be assessed on its merits, and advice sought from either the local Master Thatcher′s Association, or a fully experienced and reputable thatcher.

In order to verify the feasibility of different techniques, this chapter further studies the adaptability of two massive straw biomass applications in rural areas in China.

The methods of assessing biomass power generation project with Life Cycle Assessment (LCA), survey and field test of one biogas station, and game-theoretic analysis are adopted.

The following conclusions can be drawn: The air pollution costs account for more than 60% of the total environmental cost, followed by depreciation expense and maintenance fee of 18%, compared to that of biomass power generation at 0.01711 CNY/kWh. The adopted greenhouse sunlight technology of Solar Biogas Plant in Xuzhou, China, raises the inside average temperature by 11.0 °C higher than outside and keeps the pool temperature above 16 °C in winter, ensuring a gas productivity of biogas project in winter up to 0.5–0.7 m³/m³ by volume. This chapter also analyzes the information cost incurred by asymmetric information in biomass power generation via game theory method and illustrates the information structure with game results. It provides not only a foundation for the policy research in promoting straw power generation but also theoretical framework to solve the problem of straw collection.

These studies will propose solutions to relevant problems arisen in the running process.

These studies are all based on real cases, field research, and appropriate theoretical analyses, so, they can reduce the relevant costs and promote the application of relevant technologies.

This study analyzes the factors which affect the alfalfa cultivation acreage in China and estimates the development of alfalfa planting by the supply model.

Based on the characteristics and actual conditions of alfalfa cultivation in China, a naïve empirical model was created to analyze the impact of various influencing factors on the cultivation acreage of alfalfa.

The analysis of influential factors shows that China's alfalfa planting conforms to naïve price behavior. The prices of alfalfa and per capita arable land occupancy have a positive effect on the cultivation acreage, while the price of competitive crops and transportation costs have a negative effect on the production of alfalfa. Lastly, the 2012 alfalfa subsidy policy has a significant negative impact on alfalfa cultivation acreage.

Due to the limited research on alfalfa supply in China, there is a lack of available research data and statistical data. A large number of data in this study are mainly indirect data derived and calculated from other industrial data. The measurement results may not be fully accurate.

This study represents the first empirical analysis of the characteristics of the factors influencing alfalfa cultivation acreage in China. The secondary data were used to analyze the influence of various control variables on the cultivation acreage of alfalfa, which is different from existing research.

The global population explosion and the accompanying industrialisation have resulted, on the one hand in an increase in wastewater volumes and an almost innumerable list of constituents, and conversely, in an increasing shortage of water resources and basic food supplies, at least in some regions of the world. Current technologies enable almost all constituents to be eliminated from wastewater assuming the necessary financial resources are available, but appreciable quantities of sludge are produced. However, this handicap can be turned to advantage: sludge, when transformed into biosolids, is an ideal soil conditioner and fertilizer in agriculture. Thus the supposed threat of increasing waste can be transformed into a bonanza ‐ if operationally efficient logistics, administration and cost management systems are in place. Outlines current wastewater treatment practice in Germany, including the applicable directives and guidelines.

One of the objectives of smart village is the efficient use of regional resources by local people to improve economic, social and environment conditions. Small-scale dairy farm (SDFs) exist in every village of India, contributing significantly to local economy and welfare of few families. The purpose of this work is to develop a mechanism to make SDF not only efficient but effective in operations.

A systems thinking approach is used to identify the variables influencing a SDF and develop a general framework – RAMHI (resources, alternate revenue, manpower, herd and infrastructure) comprising endogenous and exogenous variables. A representative SDF as a case study was chosen to implement RAMHI and assess its implementation feasibility and economic benefits.

Implementation of RAMHI gradually improves the economic benefits of a SDF. The key performing indicators like average milk produced/day; milk revenue/fodder cost; number of successful artificial insemination (AI) of herd/number of AI of herd; milking cow/dry cow; and milking cow/total cow, increased substantially in two successive years.

The literature reported and discussed individual variables influencing functioning of SDF while there are few conceptual frameworks proposed, comprising not more than three variables. This paper not only presents a comprehensive generalized framework – RAMHI, which comprises five variables like resources, alternate revenue, manpower, herd and infrastructure but also explains the implementation strategy and its benefits using a case study.

Bioenergy as a renewable energy type is found as a promising method to replace non-renewable energy. Anaerobic co-digestion, in which the microorganisms of two or more substrates break into biodegradable materials without oxygen, and fermentation, in which substances break into a simpler form in the presence of microorganisms and some bacteria, are the two frequently used methods that are were applied in this work.

A farmland currently being used for farming was selected, and the bioenergy potential of the farmland was evaluated by using the aforementioned two methods. In this work, segregated municipal wastes which were collected from nearby areas and animal manure were used as feedstock for anaerobic co-digestion, whereas wheat straw obtained from the farmland was used as feedstock for fermentation.

The total input energy required for the digestion systems and the collection of the feedstock products from the growth to the harvest phases was calculated. Thereafter, the generated output energy was calculated to obtain an energy balance of the techniques. All the processes were taken into account during the prediction of the cost of the given power plant. The power output capacity of the farmland was 245 MW with a total cost of $540,200.

Because of the chosen research approach, the research results may lack generalisability. Therefore, researchers are encouraged to test the proposed propositions further.

The result proves that the two methods were applicable and feasible to replace for the 200 ha farmland.

This article aims to focus on the food value of the mushroom. Because of its low calorific value and very high content of proteins, vitamins and minerals, mushrooms may contribute significantly in overcoming protein deficiency in developing countries like India.

Oyster (Pleurotus sajor caju) mushroom cultivated on two substrates i.e. wheat straw and brassica straw were procured. Freshly harvested and washed mushrooms were cut into small pieces. Sliced mushrooms were divided into four portions. Two portions were left untreated and dried using sun and oven drying methods. The third portion was blanched in boiling water at 100 °C for two mins, cooled immediately and drained. The blanched samples were divided into two portions. One portion was sun dried and another was oven dried. The fourth portion was soaked in solution of citric acid (0.25 percent) for 30 mins and drained. The steeped samples were divided into two portions. One portion was sun dried and another was oven dried. Each sample was dried from initial moisture content of 91 percent on fresh weight basis of the final moisture content 10 percent on dry weight basis. All the samples were ground to make fine powder. The untreated and treated samples were analysed for physico‐chemical properties and sensory evaluation by using standard methods.

Treated and untreated powders prepared from oyster (Pleurotus sajor caju) mushrooms grown on two substrates i.e. wheat and brassica straw were analysed for physical and chemical characteristics. Among the powders, T₆ (steeped in 0.25 percent citric acid and oven dried) powder exhibited highest yield followed by untreated and blanched powders. On the other hand, untreated samples T₁ (sun dried) and T₄ (oven dried) showed higher browning index as compared to pretreated powders. Steeped samples (T₃ and T₆) from both type of mushrooms, irrespective of drying methods exhibited higher values of water retention capacity and swelling index as well as sensory attributes (colour, aroma and texture) In terms of chemical analysis, steeped samples from both types of mushrooms, irrespective of drying methods, exhibited higher contents crude protein, crude fibre and ash as compared to blanched powders. Blanching in hot water may cause leaching out of nutrients.

With regard to healthy benefits and medicinal value of mushroom, its production and consumption should be increased. However, mushroom production does not demand land, but helps in the bioconversion of potential pollutants like agro‐wastes to useful and nutritive food for human consumption, which is essential to a developing country like India.

The findings of this article may contribute significantly in overcoming protein deficiency in developing countries like India. Mushrooms have a low carbohydrate content, no cholesterol and are almost fat free. Therefore, they form an important constituent of a diet for a population suffering from atherosclerosis.

The purpose of this paper is to study the possibility of preparing high performance, agro‐based composites from rice straw, using eco‐polyalcohol polymers‐based adhesive system. The utilization of rice straw (undesirable biowastes) for the production of high quality biocomposite products, will add economic value, help to reduce the environmental impact of waste disposal and, most importantly, provide a potentially inexpensive alternative to the existing commercial artificial wood‐panels.

Simple synthesizing and optimizing the polyalcohol polymers‐based non‐toxic adhesive system were carried out, by blending corn starch, as natural polyalcohol polymer with polyvinyl alcohol, as synthetic polyalcohol polymers‐based adhesive (St/PV adhesive), at temperature ∼75°C. The percentages of adhesive components, type of starch, bonding temperature and time were optimized. Assessment of the synthesized adhesive was performed from its adhesion behavior (bond strength), in comparison with commercial thermosetting resin (urea‐formaldehyde), as well as the properties (mechanical and physical properties) of the composites produced. The effects of amount and type of water resistance co‐additives (paraffin wax and polyester), on mechanical properties of RS‐based composite were also optimized.

The promising adhesive system exhibits improved performance over a previously commercially HCHO‐based adhesive (UF), and results bonding strength 9.8 N/mm2, as well as MOR, IB and TS of RS‐based composites up to 31 N/mm2, 0.49 N/mm2 and 20%, respectively.

Through the studied eco‐adhesive with relatively high natural polyalcohol polymer (starch) in presence of water‐resistance additive (PE) provided a good bonding strength and comparative RS‐based composite properties, with that produced from commercial UF. For the mechanical properties (MOR and IB) are complied the standard values; while water resistance is still higher. Further study is needed to solve this problem.

The approach provided a HCHO‐free adhesive with good bonding strength, comparative board strength and water resistance, reasonable working life, and without formaldehyde emission. Starch‐based adhesive with low percentages of polyvinyl alcohol is considered a promising inexpensive alternate adhesive in wood industry based on rice straw wastes, which traditionally required expensive pMDI.

The paper provides a potential way to utilise undesirable rice by‐product (RS), corn starch as industrial raw material. This will benefit farmers significantly. Meanwhile, the modified starch adhesive with low percentage of PVA is promising to partly or completely replace urea formaldehyde resin and pMDI that are mainly used in wood industry, or pMDI in RS‐based artificial wood, avoiding formaldehyde emission or toxic gases during exposed to burning, and reducing the dependence on petroleum products.